TypeScript's type system is incredibly powerful. It can represent bizarrely complex interdependent JavaScript types and comes with a Turing-complete set of logical conditions. But this is a React conference, right? Let's implement a primitive React purely in the type system. For fun!

Most CSS developers today write visual styles in terms of what you literally see: exact color values, size numbers, and so on. But what if you could write styles as a function of how they fit into your design system? And what if you could get type safety in specifying and using those values, including in responsive props?
This talk will dive into some of the key features and flaws in many design system builders today such as Chakra UI and Tailwind. We'll establish what the best next steps for design systems should be with type-safe TypeScript APIs and performance both for prebuilt pages and at runtime.

Next.js and other wrapping React frameworks provide great power in building larger applications. But with great power comes great performance responsibility - and if you don’t pay attention, it’s easy to add multiple seconds of loading penalty on all of your pages. Eek! Let’s walk through a case study of how a few hours of performance debugging improved both load and parse times for the Centered app by several hundred percent each. We’ll learn not just why those performance problems happen, but how to diagnose and fix them. Hooray, performance! ⚡️

There are amazing tools out there providing you with excellent type safety. But when you get to the client-side fetching, things go wild. Even if you have perfectly typed backed, you lose the type information during the client-side communication. Yes, you can use GraphQL or protobuf and generate types, but... what if I told you there's an easier way? A way that lets you develop your apps smoother than with REST or GraphQL? How? RPC! Say hi to maximum productivity with fantastic developer experience.

Modern frontend applications want to efficiently query data on page load and navigate, format the data with TypeScript, and cache data between repeat requests. Setting that all up on your own is a chore... but with Apollo and Next.js, you can set up your client to auto-generate TypeScript types, cache query results intelligently, and generally be a breeze to work with.

TypeScript is great, but migrating an existing app to it can be a pain. Codecademy took multiple existing React apps and converted them to TypeScript. We'll cover how to make those kinds of conversions successful from both cultural and technical standpoints.